An impromptu shrine appeared on the site in Moscow where Russian opposition leader Boris Nemtsov was killed. Among those paying their respects were opposition politician Anatoly Chubais and U.S. Ambassador John Tefft. (Reuters)
Ukrainian President Petro Poroshenko says Russian opposition politician and Kremlin critic Boris Nemtsov was killed because he was going to reveal evidence of Moscow's involvement in the separatist conflict in eastern Ukraine.